Method and apparatus for extracting values from coal and the like



Sept. 9, 193@. F, c, GREENE El AL 1,775,280

FOR EXTRACTING VALUES FROM COAL AND THE LIKE METHOD AND APPARATUS Filed April 9, 1919 N 740 C. Grdsm:

Patented Sept. 9, 1930 UNITED STATES PATENT OFFICE FRANK C. GREENE, OF DENVER, COLORADO, AND IRVING I. LAIICKS, OF SEATTLE, WASHINGTON, ASSIGNORS TO OLD BEN COAL CORPORATION, OF CHICAGO, ILLINOIS,

A CORPORATION OF DELAWARE METHOD AND APPARATUS FOR EXTRACTING VALUES FROM COAL AND THE LIKE" Application filed April 9,

The agglomeration of coal, either coarse or fine, has been heretofore accomplished either I by the action of heat, as in carbonization in a coke oven or retort, or by pressure as in briquetting, using a binder to cement together the component particles. Briquettes have also been made of such material and then carbonized. \Ve have found that superior results are secured in handling materials of the class in question by simultaneously applying ing description setting forth in detail certain .mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexed drawing Fig. 1 is a side elevation of a suitable retort and accessory apparatus adapted for the carrying out of our improved process; Fig. 2 is'a central axial section of the retort proper; Fig. 3 is a. similar section of a part of such apparatus; F ig.4 is an enlarged detail; F ig). 5 is a sectional detail similar to Fig. 2, ut showing a slightly modified construction, and Fig. (5 is a fragmentary view ofthe lower end of the "retort partly in vertical section.

Taking bituminous .coal for" example, when this is subjected to a proper heat,'it becomes soft and plastic, the degree of softness and plasticity Qvarying somewhat with different coals. Small particlesbecome attached to one another more or less, depending on the degree ofheat and the kind of coal. Gas, moreover, begins to be formed by the decomposition andvaporization of substances in the coal which, on escaping, leaves pores and bubbles. At the same time 1919. Serial no. 288,684.

the individual particles do not entirely coalesce, but are bound together rather loosely, and after the heat has increased some what beyond this stage, the coal loses its plasticity and becomes hard and brittle, or may be said to set. Accordingly, if the particles are loosely attached when' they reach this stage, they remain so in the coke product, and similarly if the pores are large, they remain unchanged in suchproduct. \Ve have found, however, that by applying pressure at the proper time, so as to closely unite or squeeze together the particles while still plastic, the pores are closed up and a coke much more dense and strong results, superior in every way to a coke which has not undergone such treatment. If desired the temperature may now not only be raised sufficiently to destroy the plasticity and to set the mass, but the latter may be .subjected to further carbonization to recover the further content of gas and oil which will be evolved upon application of such higher temperature. This further carbonization, under the conditions stated, does not apparently weaken the structure.

lVe preferably carry on the treatment just described in a continuous process, by introducing the material to be treated into the endof a vertical cylindrical retort through which a screw passes. In the zone in which pressure is to be applied, the cross-sectional area of the space between the screw and the confining walls of the retort gradually reduced, so that gradually increasing pressure is applied as the material passes through this stage. The application of heat to the retort is so regulated, as is also the speed of rotation of the screw, that the coal or other material is made to reach the zone or stage in question at 'the time when its plasticity is just right to make a product of the desired structure. By proper modification of these two factors, a coke can bepi-oduced having almost any desired structure, strength, density, etc.

-At the point of greatest constriction the heat is, raised sufficiently to set the material, the pressure being continued until such set takes place. Thecoke may then either pass x screw is leveled from the upper: face to form into a cooling chamber, whence it may be discharged by suitable mechanism (or quenching may be substituted for such cooling), or such coke may be passed through a further section of the retort, preferably having a somewhat enlarged cross-sectional area,

and there undergo further carbonization to increase the yield of gas and tar. In the first case the product will have a somewhat higher volatile content as well as density, while in the second, both such volatile content and density will be lower.

During the application of heat and pressure, the gases and vapors formed may either be removed from the material undergoing treatment, or the tar and resultant pitch therefrom formed by the heat may be allowed to remain partly or wholly in the mass undergoing treatment, thus acting as additional binding and plastic material. lVhcre removed, these volatile constituents may be allowed to escape by their own pressure or drawn off by suction as desired, and then collected and condensed by any suitable means outside of the retort.

In the illustrative apparatus shown in the several figures of the drawing is shown a vertical retort 1 of general cylindrical form disposed'within a suitable furnace chamber 2. The heating gases may enter the chamber 2 through the opening 4 at the bottom, and escape therefrom through the opening 5 at the top. "Within such tubular retort is rotatably mounted a tubular shaft 6 (see Fig. 2). the upper end 7 of which projects beyond the upper end not only of the retort proper, but of the head 8 that surmounts the latter.

Said inner tubular shaft gradually increases in diameter from apoint approxi- ,mately one-third the distance from the upper end of the retort to a point approximately half way down such retort, and then grad- I ually decreases again in diameter to a point removed about one-third the total length of the retort from the lowerend of the latter, with the result that the annular space between the shaft and the inner Walls of the retort is correspondingly constricted and then-again enlarged to normal. Said tubular shaft is provided externally throughout its length with a spiral rib or flange 9, of a width tosubstantially span the annular space thus left between said shaft and retort. The

upper face of this flange or screw is inclined downwardly and outwardly at an angle of approximately forty five degrees, while its under. face is concave, forming ac'ontinuo'us concavity around the helixof the screw,that produces a rolling and: kneadingajotio'nof the material, as will bel'presentlyidescribed in detail. The outered-ge ofasaid-flange or a cutting edge which lia'sv a clearance angle between theface of the screwan the vertical retort pf 10 more or less, as s ownthe detail view of Fig. 4. The shaft is also provided with a series of holes or apertures 10 for the escape of vapors into its interior, these apertures being located just above the upper surface of the screw 9. These aper- 7 tures may simply extend radially inwardly as shown in Fig. 2 or they may trend iii the direction of rotation of the'rotor 6 and incline upwardly, as shown in the modified construction in Fig. 5, in order to facilitate the withdrawalof such vapors. The size or number of these holes. through which the vapors may thus escape may be varied by the axial adjustment of a cylindrical shutter 11 that is fitted within the tubular shaft, as best shown in Fig- 2. This shutter can be raised or lowered as desired, through the medium of a shaft 11 attached to its upper end and extending upwardly through the head 8 as shown in Fig. 3, with the result that all the apertures will be correspondingly closed (or opened, or by a'proper arrangement of the apertures 12 in the shutter certain of. the apertures 11 in the tubular shaft may be shut off and a limited number left open, as will be readily understood.

The upper end vof the tubular shaft 18 closed by a vacuum seal consisting of a suitab e valve 15, while the lower end of each retortdischarges into a chamberltl which is likewise adapted to be sealed .bymeans of a close fitting discharge'gate l7. lhe at. tail of construction of such discharge gate need not be described since itf fo'rms no part of the present invention, being fully 'de- .1 scribed and claimed in our co-pending application Serial No. 308,714, filed July 5: 1919. Driving means 18 for rotating the tubular shaft are connected with the upper end thereof, while its interior is connected through a duct 19 with a vap'ormain 20 that, be placed under suction by means not; shown, and any desired degree of vacuum thus pro-- vided within the tube. Connected with the head 8, below th partition 2ltherein that no separates the vapor connectioiifltlfisa duct 22 through which the coal or othe r'like ma teria-l is received. from-a conveyor-trough 23 and supplied to'the u": ,per end of the retort.

Goals vary in their, egree'ofplasti'c'ity, and

the time and hatneces'sary todevelop maximum plasticity; F or this reasonthe" proper relation of these-faetors'mustbe determined for the particular coal at hand bytriahand nofixed rules can be laid'clowmi'l'n general, 1201' found sufficient, the mam ary be ma'de' ofi per surface of the spiral screw 19, hutfas-it becomes soft and"'fllasticinndertthe influencef I of heat, and-fart erino're reaches the constricted portion of the passage through the retort, its movement tends to be retarded,

and it shifts in location to the under side of the screw. As a result of the peculiar concave form of the latter, the material is here subjected to a rolling, or sort of kneading action, as indicated by the arrows applied to the dotted mass representing the material in Fig. 2. The result of this action is to make the structure of the coke, when set, much stronger and denser, the mass being correspondingly compressed, so that when the area of constriction is passed, even thou h the mass may expand somewhat, it will sti l be free to fall away from the under side of the screw and again rest on the upper surface of the same. It is finally discharged in more or less broken fragments from the lower end of the retort into the chamber 16 provided for its reception. I

As previously indicated, provision is made for applying a suction to the interior of the tubular shaft if it is desired to accelerate the rate at which the vapors are evolved during the passage of the material through the retort. The rate of evolution of these vapors is also regulablf by the position of the cylindrical shutter 1. As a result, more or less of the volatile matter may be left behind in the material to be there carbonized, and assists, by its actionas a binder, in consolidating such material.

The process is not only applicable to bituminous coal, but also to mixtures of coal or other carbonaceous material, which in themselves have no cohesive or binding properties when hot, with other materials which have plasticit when hot, such as pitch, asphalt, etc. Iiignite, for example, may be mixed with bituminous coal in suitable amount to provide the plastic material, or such lignite may be mixed with tar or pitch or other suitable binding material. The lignite thus used may be either raw or partly or wholly dried or carbonized. Likewise other carbonaceous material, such as coke breeze, or anthracite fines, may be agglomerated by this process. It is not attempted to form the product in pieces of regular shape, as in the case of briquetting processes, but merely of sufiicient size so that they may be used as fuel or coke, where the fines or raw material could not be thus used. The process, it will be observed, is a carbonization process, with simultaneous application of pressure as well as heat, and withal continuous.

Other modes of applying the principle of our invention may be employed instead of the one. explained, change being made as regards the steps or mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

We therefore particularly point out and distinctly claim as our invention 1. In a method of agglomerating carbonaceous material which may be rendered plastic and decomposed to form vapors and set by heating, the steps which comprise s-ibjecting the material out of substantial contact with air to a progressively increasing temperature to a point where the material is rendered plastic and is decomposed to form vapors, and simultaneously applying progressively increasing pressure to the material up to the point of setting.

2. The method of agglomerating carbonaceous material which may be rendered plastic and decomposed to form vapors by heating, which comprises subjecting the same out of substantial contact with air to progressively increasing temperature and pressure to a point where the material becomes p'lastie and vapors are evolved by decomposition of the material and in a constricted space, but with :1 substantial portion of the surface of the mass unenclosed, whereby the evolved vapors may freely escape.

3. T he method of agglomerating carbonaceous material which may be rendered plastic and decomposed to form vapors and then set by heating. which comprises subjecting' the same out of substantial contact with air to a. temperature where the material is rendered plastic and vapors are evolved by decomposition of the material, and simultaneously rolling and kneading the material while in such plastic state under gradually increasing pressure up to the point where the material sets.

l. The method of agglomerating carbonaceous material which may be rendered plastic and decomposed to form vapors and set by heating, which comprises subjecting the same out of substantial contact with air to a temperature where the material is rendered plastic and is decomposed to formvapors, simultaneously rolling and kneading the material while in such plastic state under graduallv increasin a) licd'" ressure u to the point where the material sets, and withdrawing the vapors evolved during the foregoing.

The method of agglomeratin'g carbonaceous material which may be rendered plastic and decomposed to form vapors and then set by heating, which comprises subjecting the same out of substantial contact with air simultaneously to temperature and pressure to a point where vapors are evolved by heat decomposition of the material and in a constricted space but with a substantial portion of the surface of the material unenclosed whereby the evolved vapors may freely escape, and simultaneously rolling and kneading the material in such constricted space.

6. The method of agglomerating carbonaceous material which may be decomposed to form vapors by heating, which comprises nous coal that may be rendered plastic and decomposed to form vapors by heating, which comprises subjecting the same to heat to a temperature where the mass is rendered plastic and vapors are evolvedby decompositionof the coal,simultaneously rolling and kneading the mass, and gradually restricting the movement of said mass while gradually applying progressively increasing pressure to the mass.

-8. The method of agglomerating bituminous coal, which comprises subjecting the same to heat to a point where themass is rendered plastic, and simultaneously rolling and kneading the mass under gradually. increasing pressure up to the point where such mass sets. 1

9. The method of agglomerating bituminous co'al, which comprises subjecting the same to heat to a point where the mass is rendered plastic, and simultaneously rolling and kneading the mass under gradually increasing pressure up to the point where such mass sets, and withdrawing the vapors evolved during the foregoing. I y

10. In apparatus of the character described, the combination of a retort adapted "to be externally heated, and means within said retort defining a space therewith and adapted to pass material through said retort, said space intermediate its ends, gradually .decreasing and then increasing in cross section transverse to the direction of travel ofv the material whereby varying pressure may .be applied to such material.

ll. In apparatus of the character described,--the combination of a cylindrical retort, and a rotatable screw within said retort extending longitudinally thereof and adapt ed to pass material through said retort, the distance between the latter and the shaft of 'said screw decreasing and then increasing along said screw whereby varying pressure may be applied to such material.

12. In apparatus of the character described, the combination of a vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extendinglongitudinally thereof, said shaft varying in diameter so as to vary the space'between the same and said retort, and a spiral screw'on :said shaft'adapted to pass material through such space, said shaft having perforations may be withdrawn into its interior. 13. In apparatus ofthecharacterdescribed,

the combination of a vertically disposed eylindrical retort, .a hollow rotatable ,j' shaft within said-retort and extending longitudinally thereof, said shaft varying in diameter so as tovary the space between the same and said retort, anda spiral screw on said shaft adapted to pass material through such space, the upper face of said screw being'inclined and its under face hollow concave.

14. In, apparatus of the character. described, the combination, of a vertically disposed a lindrical retort, a hollow rotatable shaft within said retort and extending longitudinally thereof, said shaft varying in diameter so as to vary-the space between the same and said retort, and a spiral screw on said shaft adapted to pass material through such space, the upper face of said screw being inclined and its under face hollow concave, and said shaft having perforations adjacent the upper face of said screw whereby vapors evolved from such material may be withdrawn into its interior.

15. In apparatus of the character desciibed, the combination of a vertically di'sposed cylindrical retort, a hollow rotatable vertical shaft within. saidretort, said shaft varying in diameter so as to vary the space between the same and said retort, and a spiral screw on said shaft adapted to pass material through such space, said 'shaft having perfo rations wherebyj vapors evolved from such material may be withdrawn into its interior,

and means adapted to vary the extentof such perforations.

16. In apparatus of the character described, the combination of a vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extending longi tudinally thereof, said shaft varying in di-- ameter so as, to vary the space between the same and said retort, and a spiral screw on said shaft adapted to pass material through "such space, said shaft having perforations whereby vapors evolved from such material may be withdrawn into its interior, and a cy- "lindricalshutter within said shaft movable to va the extent of such perforations.

17. n apparatus of the character described, the combination of a retort adapted to be externally heated, and meanswithin said retort and definin a space therewith and adapted topass material through said retort, the space between the wall of said retort and said meansvbeing firstconstricted and'then enlarged in the direction of travel of the material, whereby varyin'gpressure may be applied to such material.

18. In apparatus of the character described, the combination of a vertically dis- ,POSGd cylindrical retort, a hollow rotatable shaft within said retort and extending longitudinally thereof, said shaft varying in diameter so as to vary the spa'ce between the same and said retort, and a spiral screw on said shaft adapted to pass material through such space, the upper face of said screw being inclined and its under face hollow concave, the outer edge ofsaid screw being formed into a cutting edge having a clearance angle between the face of the screw and the vertical wall of the retort of approximately 10?.

19. In apparatus of the character described, the combination of a vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extending longitudinally thereof, said shaft varying in diameter so as to vary the space between the same and said retort, and a spiral screw on said shaft adapted to pass material through such space, the upper face of such screw being inclined and its under face hollow concave. and said shaft having perforations from outside to inside of the hollow shaft, each perforation extending along a line, the inner end of which is inclined upwardy and peripherally of said shaft relative'to a radial line which would intersect the axis of rotation of said shaft.

, .20. In appa atus of the character dewall of the retort of approximately 10.

tive to a radial line which would intersect the axis of rotation of said shaft.

23. In apparatus of the character described, the combination of a. vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extending longitudinally thereof, and a spiral screw on said shaft adapted to pass material through said retort, said shaft having perforations whereby Vapors evolved from such material may be withdrawn into its interior, and means adapted to vary the extent of such perforations.

24. In apparatus of the character described,

,the combination of a vertically disposed cylindrical retort, a hollow rotatable shaft with in 'said retort and extending longitudinally thereof, and a spiral screw on said shaft adapted to pass material through said retort, said shaft having perforations whereby va pors evolved from such material may be withdrawn into its interior, and a cylindrical shutter within said shaft movable to vary the extent of such perforations.

25. In apparatus of the character described, the combination of a vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extending longitudinally thereof, and a spiral screw on said 'shaft adapted to pass material through said retort, the upper face of said screw being inclined and its under face hollow concave, the outer edge of said screw being formed into a cutting edge and having a clearance angle between the face of the screw and the vertical wall of the retort.

Signed by us 1919.

I FRANK C. GREENE,

IRVING F. LAUCKS.

21. In apparatus of thecharacterdescribed,

the combination-of a vertically disposed cylindrical retort, a hollow rotatable shaft within said retort and extending: longitudinally thereof, and a spiral screw on said shaft adapted to pass material through said retort, the upper face of said screw being inclined and its under face hollow concave in lateral cross section, and said shaft having perforations adj acent the upper face and spaced from the lower face of said screw whereby vapors evolved from such material may be with v drawn into its interior. 

